Rock drill



Feb. 8; 1927.

ROCK DRILL Filed June so; 1925 7 mvENToR Mmamznsmizz,

m5 'ATTORN WILLIAM A. SMITH, or ATHENS, PENNSYLVANIAQASSIGNR :froINeERsoLL-:RAND COMPANY, 0E JERsEY CITY, NEW JERSEY, A coRPoRA'IIoN 0ENEW JERSEY.

ROCK DRILL.

Application led June V30, 1925. Serial No. 40,516.

This invention relates to rock drills,.but more particularly toa stopedrill of the hammer type in which provision may or may not be made, asdesired, for supply ing cleansing fluid to the hollow drill steel.

The objects of the invention are to produce a simple, light stope drillhaving a smooth exterior surface, by locating the distribution valvewithin the back head around the water tube if a water tube is provided.In case the drill is not provided with a water tube, a water tube guideis located within the back head which also acts as a centering pin forthe valve.

The invention is shown in one of its preferred forms in the accompanyingdrawing, in which 4 Figure 1 is a longitudinal sectional elevation of somuch of a stope drill as will serve to illustrate the device,

Figure 2 is an enlarged detail sectional elevation of the back headfandcentering pin,

Figure 3 is a side elevation of the valve, and

Figure 4 is a detail sectional elevation of the back head cover block.

Referring to the drawing, the cylinder A is provided with the.reciprocating piston B adapted to strike the anvil block C and impartblows of impact to the hollow drill steel D in the front head E. A watertube F may extend through the cylinder, piston, and anvil block into thedrill steel in the usual manner.

The cylinder A, back head G, back head cover block H, head block J andfeed cylinder K are all secured together by the usual side bolts L.Within the head block Gr and cover block H and sealed therein is shownthe hollow centering Ipin O forming both a guide for the valve and aguard for the water tube F, in case a water tube is used. If no watertube is used, the pin O may be made solid or it may be plugged. Pressurefluid is supplied through the throttle Q controlled by the throttlehandle R and the valve P controls both the inlet and exhaust of themachine. An exhaust port S is indicated in the cover block H controlledby the valve.

The valve pin OV is preferably provided with reduced ends T and U havingshoulders V and W seated in the back head Gr and cover block Hrespectively to form a tight connection.

The valve P is formed with the enlarged central head WV and the reducedend heads X and Y and the valve is thrown by pressure fiuidv by means ofthe kicker ports a and b controlled by the piston.

In the operation of the device so far described, let it be assumed thatthe piston is in its forward position as indicated in Figure l and istraveling rearwardly. Pressure fluid supplied from the throttle Q passesthrough the passage 0 to the groove 0l in the cover block H and fromthence passes through the passage e in the cylinder to the forward inletport f. rlhe valve is held in its forward position by pressure on thecentral head W since the opposite face of said head is opened to exhaustthrough the port S.. As the piston travels rear- Wardly, the kicker portb is uncovered and pressurefluid passes through the passage g to theforward end of the valve-P at the groove 7i thus moving the valverearwardly. Duringk the rearward stroke of the'piston, the exhaust fromthe rear end of the cylinder passes out through the port j and passagela around the valve to the exhaust port S. f Y

After the valve has been thrown rearwardly, the supply of motive fluidfrom the throttle to the groove cl passes directly over the valve head Wto the passage le and port j and thence. to the rear end of the cylinderto drive the piston forwardly. `As the piston moves forwardly anduncovers the kicker port a, pressure fluid passes through the passage 0'to the rearward end of the valve to throw the valve forwardly again sothat the cycle is repeated.

I claim:

In a rock drill, the combination of a cylinder and reciprocating piston,a back head, a back head cover block and a head block, a valve chamberformed in the said back head and cover block, a hollow valve pinseated-in and forming a seal with the said 'back headV and cover blockconcentric therewith Vand longitudinal to the axis of the machine, ahollow sleeve valve surrounding and slidable upon said hollow pinadapted sesl to reoiproeate within the valve chamber in saiolv back headand cover block and to cooperatel with ports n saJio'l` back-head andcover blockjfor admitting motive fluid to 5 the said cylinder, meansmounted in the said head block for controlling the supply of pressurefluid to the said valve, and a water tube rextending `through saidiollow Valve pin, whereby Water is prevente from entering the valvechamber. 10

In testimony whereof I have signed this Y specification.

WILLIAM A. SMITH.V

